The present invention relates to an ammunition in general and more particularly to a cartridge-less bullet. Still more particularly, it relates to a cartridge-less bullet which can be electrically fired.
Bullets without cartridges have already been developed, the impetus being the rather high weight of the cartridge casing and the expense thereof. It was reasoned that both the weight and the expense could be eliminated if it were possible to eliminate the cartridge. Development in this field has resulted in various cartridge-less bullet constructions of which two types have been found heretofore quite acceptable, namely, a type having a solid charge and a percussion firing cap, and another type having a charge of compressed gunpowder which has to be ignited by means of compressed air that is produced in the weapon itself.
It is known that it has also been repeatedly attempted to provide cartridge-less bullets which could be electrically ignited, i.e., fired. It was suggested to adhere a thin metal foil to the rear end of the explosive charge of the bullet and to burn through this foil by means of two electrodes through which a current is passed, thereby igniting the propellant charge. Wire bridges have also been suggested for the same purpose.
However, heretofore none of these suggestions for electrical firing have been found feasible. Where the foil has been used it has been found that an extremely high currnt was required to obtain the desired result. Where the wire bridge was used there was insufficient certainty of electrical contact. In any case, however, the main objection has been that metallic deposits on the electrodes cause difficulties leading to a non-reliable operation of a weapon which uses such bullets.
Another field in which electrical firing has been used for some time now are blasting caps and the like. Here, firing caps have been used which contain mixtures of conductive materials and explosive materials, such as lead styphnate, copper acetylide or lead azide. These caps are fixedly connected with the electrodes which are in turn connected with the ignition charge and are either destroyed after use (as in the case of blasting caps) or must be subsequently removed (as in the case of electrically fired bullets having cartridges where the use of such type of caps is also known). In either case it is of no importance whether the conductive materials and the explosive materials used tend to form deposits on the electrodes or not, because the electrodes are not and cannot be re-used.
The matter is different in the case of cartridge-less bullets which are to be electrically fired, because in this instance the ignition electrodes are a part of the firing weapon and remain there, being required to remain operative for thousands of rounds of ammunition. For this reason the use of cartridge-less bullets must never under any circumstances lead to fouling of the electrodes, as by the deposits of material on them. Furthermore, it is necessary that this type of ammunition be unaffected by blows, by friction and by moisture despite the fact that it is exposed, unlike conventional ammunition which is protected in the cartridge.